Abstract

This content analysis recorded graffiti inscribed onto bathroom walls within nine local bars in a medium-sized Midwestern city. The researchers coded 1,201 inscriptions for elements tied to evolutionary psychology and previous research on graffiti. The results indicated that males, compared to females, composed more sexual, homosexual, and presence identifying graffiti. Additionally, males drew more stand-alone images and authored more graffiti overall. However, females authored more romantic, interactive, and insulting graffiti. Many of the findings are largely in line with evolutionary psychology and some reaffirm the results found by previous research.

In a bar restroom just off campus, on a brightly colored stall wall, an anonymous author etched “…That’s what she said” in bold black ink. Immediately below this message, another author scratched out the she and replaced it with “Your mom.” Was this a clever insult? Perhaps not. But this exchange that occurred over an indeterminable amount of time contains many levels of nuance. The joking author who composed …that’s what she said was likely referencing a line made popular by the successful television show The Office. “That’s what she said” is meant to be a sexually charged joke that one can append to anyone else’s sentence, instantly turning the target’s seemingly benign statement into a sexual innuendo. The insulting author, however, turned the jest back on the jokester with an insult that trumped the humor and called into question the mother of the jokester’s chastity.

Rather than being simple wall markings, graffiti openly reveals a number of psychologically grounded tendencies and motivations that are typically latent within other settings. Although the digital age offers no shortage of public venues in which people can express their attitudes (e.g., Twitter and Facebook), writing on walls persists. It would seem that the veil of anonymity preserves the appeal of graffiti, as it allows the user of a bathroom stall to express any view, thought, or declaration covertly. This leads to people sharing information they would not publicly, such as sexual propositioning and cruel insults. Moreover, these messages have social consequences. For example, one article (Barnett, 2006) reported that a student wrote his male friend’s phone number on the bathroom wall in a men’s restroom. The act resulted in numerous phone calls from men inquiring about sex.

Sexual messages are common and drive the existing research on graffiti. Although the bulk of these studies occurred during the 1970s, research over the past 40 years has been much more sporadic, which alludes that the literature may be outdated. What exists suggests a discrepancy over interactive graffiti written by men and women and the prominence of sexual content. Furthermore, evolutionary psychology acts as a powerful framework for predicting and explaining socially sexual phenomena. Despite this, it is largely absent from previous work.

Given the limited current research on graffiti and its strong ability to report on anonymously, yet publicly shared social attitudes, this study provides a much-needed present-day addition to the literature. Additionally, the utilization of evolutionary psychology provides an alternative perspective for approaching and discussing graffiti. The central focus then of the current study is to investigate the differences in content between male and female-authored graffiti grounded in evolutionary psychology. To fulfill this goal, we content analyzed graffiti from the bathroom stall walls of nine bars in a Midwestern college town.

From Cave Art to Bathroom Graffiti

From time immemorial, humans have sought to leave their mark on surfaces, whether in the form of writing, pictures, or symbols. The locations of these markings vary tremendously from caves and trees to tables and toilet stalls. The word graffiti itself is broad in meaning, as it is derived from the Greek term grapheon, which means ‘to write’ (Phillips, 1996). In recent times, graffiti is understood to encompass writing or pictures of any kind on a multitude of surfaces and is very often considered deviant due to its vandalistic nature.

There are three primary categories of graffiti. The first, tourist graffiti, is found predominantly on rocks, picnic tables, tree trunks and monuments and mostly consists of names and dates. Inner-city graffiti is the second category and is identified by the authors’ concerns for their own names and identities as well as territorial gang markings. Inner-city graffiti is typically found on large building walls, subways, and bridges. Finally, latrinalia, in reference to a study by Dundes (1966), is the third type of graffiti. It refers to the pictures and messages found in the latrine or toilet cubicle (Anderson & Verplank, 1983).

In terms of category, latrinalia is the sole focus of the current study. This type of graffiti is most appealing due to three primary characteristics. The first is its ability to act as a barometer for social and cultural events. This ability is driven in part by the inherent privacy a bathroom stall offers users (Anderson & Verplank, 1983). The promise of anonymity allows authors to compose somewhat public messages that are relatively free from social pressures.

The second characteristic of latrinalia is its endurance, which is shared to some degree by all three types of graffiti. In an age when the social networking giant Facebook boasts 845 million active users (Facebook, 2012), it is peculiar that something as seemingly quaint as wall etchings still exists. Rather than a passing comparison, the web 2.0 trend of commenting and otherwise leaving one’s mark in the digital realm has a striking connection with graffiti. In many ways, one could think of these examples found in emerging media as modern day manifestations of cave paintings or hieroglyphics—the next evolutionary stage in the history of graffiti. Even the terminology found on social networking sites bears a resemblance to graffiti. For example, on Facebook, the place where all public communication occurs is called The Wall. Nevertheless, despite the opportunities to leave digital markers in the online environment, writing on walls continues in the form of bathroom graffiti.

The third and final characteristic of latrinalia is its audience. This final component strongly places latrinalia in a unique position. Rather than speaking to a single friend or to the general masses, bathroom graffiti speaks strictly to the author’s sex. Indeed, these stall walls may be one of the few places in the world that guarantees a staggeringly diverse audience along all but a single dimension. This allows authors to speak about gender-specific issues, irritations, and celebrations; yet, it also enables gendered attacks and derogations. In this way, the conversations that occur on stall walls may provide evidence for gender-specific thoughts and behaviors as predicted by evolutionary psychology. As intimated before, whatever it is that compels people to make marks on walls, has existed since prehistoric times.

Our perspective, as guided by evolutionary psychology, holds that humans have old brains that have evolved over a great span of time. Despite the vast differences modern society has compared to prehistory, our minds still act in response to primordial drives. These tendencies are not necessarily—or even mostly—conscious. Rather, they are backstage motivators that guide thoughts and behaviors to seize positive opportunities and avoid negative possibilities. Using this framework allows the formation of hypotheses along sex differences, as a primary focus of this perspective is mate selection and attraction (Buss & Schmidt, 1993; Buss, 1994).

In the remaining review of the literature, we present previous work on graffiti and attempt to incorporate evolutionary psychology into each category of inquiry. In this way, the current study develops hypotheses guided by previous literature but built upon psychology.

Previous Content Analyses on Graffiti

The study of bathroom graffiti received significant attention in the 1970s but more recent studies are less common. The existing research focuses on three primary topics: sex differences, sexuality, and the prevention of graffiti. Due to their popularity and applicability to evolutionary psychology, the extant literature on sex differences and sexuality are of primary interest to the current study.

Alfred Kinsey and colleagues conducted one of the first and most groundbreaking studies of bathroom graffiti in 1953. Kinsey made influential and long-standing claims about the importance of studying bathroom graffiti as a source of information on the suppressed sexual desires of men and women. Their findings revealed a profound difference in graffiti content between the sexes. Specifically, 86% of inscriptions in men’s bathrooms were erotic in nature compared to just 25% in women’s bathrooms.

Following Kinsey et al. (1953), many studies revisited the topic of contrasting prevalence and sexuality across sex. In general, the findings vary but most suggest that males compose more graffiti overall (Arluke, Kutakoff, & Levin 1987; Kutakoff, 1972; Otta, 1993; Stocker et al., 1972) and more sexual content (Farr & Gordon, 1975; Wales & Brewer, 1976). However, a few studies challenge this conclusion. For example, Otta et al. (1996) found that age drove sex differences in regards to quantity. Their results indicated that females authored less graffiti than males in secondary schools but this difference vanished in college bathrooms. Similar studies have also found no sex differences (e.g., Schreer & Strichartz, 1997). Finally, the results by Bates and Martin (1980) indicate a total reversal from Kinsey et al. (1953). They found that women, compared to men, wrote more graffiti overall and more sexual graffiti as well.

In explaining these results, the aforementioned literature is rife with sociological rationalizations. For example, Kinsey et al. (1953) argued that males write more sexual graffiti because they find it sexually stimulating. Further, they claim that women write less because of their greater sensitivity for moral codes and conventions and because they do not find graffiti arousing. Farr and Gordon (1975) explained sexual differences occur due to the societal pressures on males to be sexually active and the emphasis on females to be proper. Similarly, Arluke et al. (1987) suggested that gender roles such as conventionalism and passivity influenced females. Although these explanations are informative, an evolutionary perspective may provide a greater justification and insight into the phenomena at hand.

Given latrinalia’s sex-specific audience, it is likely that certain evolved mechanisms come into play. The first and most applicable drive is the desire to find and attract mates for reproduction. Each sex has different motivations on this regard due to what each considers reproductive success. Females are driven to establish a long-term mating strategy. This is due to the high cost of pregnancy and child rearing. Because of this, males able and willing to provide support either through resources or sharing the load of child rearing attract females the most (Buss & Schmitt, 1993). On the other hand, males are driven to seek a short-term mating strategy. Because males have a much lower parental investment, they measure reproductive success by the number of fertile partners they encounter. Males aim to minimize cost, risk, and commitment, as partner number mostly limits their reproductive success (Buss & Schmitt, 1993; Trivers, 1972).

Because of the importance of sexual success, techniques aimed at protecting partners and elevating one’s status abound but are notably different between the sexes (Buss & Shackelford, 1997). According to Campbell (2005), females tend to declare their relationships to identify their partners to others and thus stifle the partner’s potential for infidelity. Additionally, to attract their partners, females enhance their physical appearance and threaten their current partners with sexual disloyalty. As a result, males consider faithfulness a more important characteristic for their partners to have, compared to women.

Conversely, to prevent the loss of their partners, males occlude their relationships. In conjunction with this, they also threaten and act violently toward competitors. Because females value long-term bonds and the ability for their partners to provide resources, males attempt to preserve their relationship partners by complying with their partners’ desires (Campbell, 2005). Further, males try to exude qualities associated with wealth and resources such as ambition, self-confidence, authoritativeness, and status (Buss, 1994; Sadalla, Kenrick, & Vershure, 1987).

Based on the aforementioned research, it seems likely that bathrooms may act as venues to display many of these sex-specific strategies and tendencies. However, bathrooms also commonly feature a great deal of homosexual latrinalia, which would appear to convolute these sexual strategies. Graffiti of a homosexual nature, at times, comprises the majority of male messages rather than being sporadic examples (Dundes, 1966; Kinsey, 1953). As mentioned before, previous researchers posited that the generally nonreactive nature of graffiti makes it a good method for studying human attitudes (Bates & Martin, 1980; Webb et al., 1966). For example, Flores and Sechrest (1969) used graffiti as a measure for differing attitudes toward homosexuality. In this sense, graffiti can act as a private and semi-permanent bastion for homosexual expression.

Although evolutionary psychology on the surface appears to fall flat in explaining homosexuality, research by Symons (1979) explains that homosexuals use the same tactics to attract and preserve relationships. More specifically, heterosexual and homosexual males have similar behaviors such as monopolizing their mates’ time, punishing the threat of infidelity, intimidating competitors through derogation, and sexual inducement (Vanderlaan & Vasey, 2007). This occurs despite the omission of paternal investment.

Because of these factors, we posited that the content of latrinalia would exhibit evolutionary-dependent sexual strategies. The literature on graffiti suggests that males would compose more messages about sex (Bruner & Kelso, 1980). Literature based on evolutionary psychology would agree, as males should be more likely to discuss their success at sex as evidence of their successful mating strategy. Conversely, females should be more likely to avoid authoring messages involving sex due to their motivation not to appear sexually promiscuous. Based on these tendencies, we predict the following:

H1: Males will compose more sexual graffiti than females.

Females commonly make relationships public to inhibit their partners’ ability to take on additional mates. This tendency results from females’ drive to establish long-term relationships. According to Buss (1994), displays of love are indicators of long-term commitment and are the most effective in securing permanent mates. Similarly, research by Kinsey et al. (1953) predicted that females would compose more romantic rather than sexual graffiti. However, the authors predicted this result under the hypothesis that women would be more conservative and morally conscious compared to males. The mating strategy of males, on the other hand, aims to engage as many mates as possible. This drive motivates males to be far less strict during mate selection compared to females. Additionally, short-term mating compels males to hide relationships to increase the possibility of attaining additional mates. In line with this tendency, a study by Green (2003) found that men propositioned for sex more often than women and the vast majority of the messages were homosexual in nature. These strategies and findings lead to the following hypotheses regarding latrinalia:

H2: Males will compose graffiti propositioning for sex more often than females.

To fulfill the latter, males derogate same-sex rivals by making negative comments about their resource potential. Similarly, women denigrate female rivals by attacking their physical appearance or fidelity. Male aggression manifests primarily as physical, direct aggression. Conversely, female aggression tends to appear as relational aggression, which is more indirect (Archer, 2004). When a female derogates a rival, it diminishes both males’ and females’ perceptions of the rival’s attractiveness (Fisher & Cox, 2009). As explained by Gallup, O’Brien, and Wilson (2007, pg. 259), “the use of indirect forms of aggression can produce negative perceptions of rival peers, and may provide a fitness advantage to the aggressor.” Taken together with the finding by Vanderlaan and Vasey (2007) that suggest that homosexuals use similar sexual strategies, it is likely that females would author more graffiti containing insults. Nevertheless, this conclusion is at odds with previous work on latrinalia. This prompts the following research questions:

RQ1: Will males or females compose more interactive graffiti?

RQ2: Will males or females compose more insulting graffiti?

Existing analyses (Green, 2003; Otta et al. 1996) on latrinalia discuss the prevalence of personal markings indicating the author’s physical presence. Names, initials, and group affiliations are elements that embody this type of graffiti. Conclusions based on the literature are mixed surrounding which sex produces more of this type of graffiti. Green (2003) found that males, rather than females, authored more statements of physical presence in bathrooms and public study booths. Inversely, other studies (Kutakoff, 1972; Otta et al., 1996) show that females inscribe more messages indicating physical presence. Although previous research on graffiti provides inconclusive results regarding physical presence across gender, evolutionary psychology illustrates a discernible difference. It is possible that indicating physical presence is the equivalent of marking one’s territory to deter rivals. Because of this, it is likely that males will compose more presence-referencing messages. However, the lack of consensus within the literature prompts the follow research question:

A small amount of research on graffiti (Green, 2003; Otta et al., 1996) included analyses on pictorial graffiti (i.e., images). These studies suggest that males draw more images than females. However, the extant literature largely ignores pictorial graffiti. This is somewhat surprising given the primacy of human receptiveness to visual processing compared to written text. As stated by Grabe and Bucy (2009), “Image processing is so efficient that basic recognition and emotional responding occur well before registering in conscious awareness” (p.13). Additionally, Malamuth (1996) researched the significance of visuals from a psychological perspective and recognized differences between the sexes. Specifically, visual stimuli more commonly attract males whereas auditory and tactile stimuli attract females. Because of this, we put forth the follow hypothesis:

H5: Males will compose more pictorial graffiti.

Finally, as previously discussed, males tend to compose more graffiti than females; although, there are a few studies that found the opposite. Unfortunately, evolutionary psychology is unable to identify a sole motivator capable of predicting which sex would compose more graffiti overall. For example, one could argue that males should compose more due to their tendency to mark territory and discuss sexuality. However, one could just as easily claim females should author more messages to identify their relationships and derogate rivals. Because of this, we ask the resulting research question:

RQ4: Will males or females compose more graffiti?

The current study sought to update the existing literature on latrinalia from a perspective informed by evolutionary psychology. Along multiple avenues, evolutionary psychology agrees with previous investigations on graffiti. However, some differences arise.

Method

Sampling
The current study sampled stall walls from 9 local bars in a medium-sized Midwestern college town. We opted to employ purposive sampling, as we could not find a complete list of all public bathrooms. Furthermore, a random sample could have resulted in very little graffiti, as there would be no guarantee whether or not the selected establishment contained graffiti. Bars located in the downtown area along the two most popular streets were sampled. Only establishments with separate men’s and women’s restrooms were included (i.e., shared/unisex restrooms were excluded). This guaranteed the gender of each author, as we assumed that males authored all graffiti in men’s restrooms and females authored all the graffiti in women’s restrooms. None of the included bars catered specifically to the gay community. Nevertheless, the locales were located in a progressive and gay-friendly town. Because of this, it is likely that at least a small portion of the patrons were homosexual.

Within each restroom, we sampled the interior stall walls for graffito, or, in the case of single-toilet restrooms with a closable door, all of the walls. The issue of privacy drove this decision. More specifically, because the act of authoring graffiti is deviant and the resulting content is often sexual, it is likely that authors would be more willing to write freely and without restraint when a restroom provided anonymity.

To avoid inconveniencing bar owners and patrons, we collected the sample early in the day. Digital photographs were taken with cameras featuring at least a 3.0 mega-pixel resolution to ensure image clarity. All photos were taken in a single day to avoid any event-related inconsistencies (e.g., the home team winning an important sports event).

For each stall wall, we took many close-up photos and then combined them to make single composite images of entire walls using photo-editing software for later coding. This technique allowed us to keep track of the location of each graffito and find even the smallest instances of graffiti.

Coding

Our units of analysis were single instances of graffiti (graffito). We transcribed 1,201 graffito from the composite images. All transcriptions were typed into a word processor for later analysis. All coding of image-based graffiti did not rely on a transcription but used the original images as reference. Any graffito that was unreadable was not transcribed unless the instance was a tag. A tag is any unique word that is meant to symbolize the author. Tags are similar to names and are often look more like abstract shapes than they do words. Lastly, they commonly occur (and reoccur) in outdoor urban settings. We considered a shape a tag if it (1) occurred more than once within the sample and (2) all of the coders agreed that the shape did not appear to be an image or random unreadable word.

Each of the authors coded one third of the sample. First, we determined the graffito’s dominant frame, choosing from sexual, socio-political (e.g., religion, politics, race, etc.), entertainment (e.g., music, television, etc.), physical presence (i.e., the writing of one’s name or the name of a group to mark territory or commemorate an event), love/romance, scatological (i.e., reference to defecation or feces), and other. More specifically, we coded graffiti as sexual if it referenced any form of sex, masturbation, or promiscuity or was propositional in any way. Romance, on the other hand, was graffiti that referenced love either textually or symbolically (e.g., drawing a heart around names). Moreover, to fit this frame the graffito could not allude to a sexual relationship between individuals.

If the graffito was coded as sexual, we first determined whether or not it was propositional in nature. For example, we coded graffito as propositional if it appeared to seek a sexual encounter by providing a phone number or a meeting time/place.

Second, we determined the sexual orientation of the graffito (this was also performed if the graffito was categorized as having a love/romance frame). Recall that we determined the gender of the author by restroom in which we recorded the graffito. Because of this, the comment I love Jim would be heterosexual if found in a women’s restroom but homosexual if found in a men’s restroom. However, the comment Pam loves Jim would be coded as heterosexual regardless of where it was found. Finally, ambiguous references were determined by unanimous voting among the coders. If a consensus could not be met, the sexuality was categorized as indeterminable.

Next, we coded whether or not the graffito was interactive or independent. For the purposes of this study, interactive was defined as graffiti that either (1) was in response to other graffiti or (2) elicits referential graffiti. Groups of interactive graffiti were typically obvious to identify, as they referenced each other or the same topic and employed the use of arrows or other visual relationship indicators. We used the grouping of individual words, handwriting, and writing implement (e.g., pencil, pen, marker, knife, etc.) to determine if the graffito was completed by a single author in a single sitting.

Regardless of category, we indicated whether or not the graffito was implied as an insult. If the message primarily appeared to put someone or some group down by making fun of them, we considered it insulting. However, graffiti that simply attempted to elicit an aggressive response such as self-referential messages without a target (e.g., kiss my ass) were not considered insults.

In terms of pictures, we coded if the graffito was solely a picture, just text, or both pictures and text. Pictures included symbols, diagrams, and drawings but excluded Greek letters.

Reliability

Prior to coding the entire sample, inter-coder reliability was established using 99 instances of graffito as training cases. The average pre-coding reliability across all categories was .89 and each category was at or above .85 (Krippendorff’s alpha for nominal variables). To determine post-coding reliability, we randomly selected nearly 19% of the 1,201 cases to recode. Post-test alphas were as follows: dominant frame (.89), insult (.88), picture (.93), interactive (.93), sexual orientation (.85), and propositional (.94) using Krippendorff’s alpha for nominal variables.

Results

By only sampling stall walls, female graffiti was grossly overrepresented, as there were 50 female stalls and only 17 male stalls. Due to this discrepancy, all following analyses were performed using the percentage of comments within gender to control for the number of stalls. For example, if males (N = 424) produced 49 graffito about religion and females (N = 777) produced 59 graffito about religion, rather than comparing the raw scores (49 vs. 59) we compared percentile scores (12% vs. 8%).

The first hypothesis predicted that males would produce more sexual graffiti. Observing dominant frame (see Figure 1), this hypothesis was confirmed, as 17.3% of male comments were sexual compared to only 13.6% of female comments. This difference was significant, as indicated by a Chi-Squared analysis, χ2 (6, N = 1201) = 95.71, p < .001 with an effect size of φc = .28 using Cramér's phi.

Hypothesis 2 posited that males would produce the greatest amount of sexually propositional graffiti. This was not supported. To test hypothesis 2, we only selected cases that were sexual in nature (according to dominant frame). Then we determined what percentage of comments was propositional within each gender. Men produced propositional graffiti (19.2% within gender) nearly twice as often as females (10.7% within gender) but the difference was merely trending. A Chi-Squared analysis revealed the lack of significance, χ2 (2, N = 176) = 2.53, p = .11.

Hypothesis 3 predicted that females would write more romantic graffiti compared to males. Observing dominant frame, this hypothesis was supported. While only 3.1% of male graffiti was romantic, 23.2% of female graffiti was of this nature. According to a Chi-Squared analysis, this difference was significant, χ2 (6, N = 1201) = 95.71, p < .001 with an effect size of φc = .28 using Cramér's phi.

Our fourth hypothesis predicted that males, rather than females, would inscribe more homosexually oriented graffiti. To calculate this statistic, we selected cases under either the sexual or love/romance frame. Then we assessed whether the graffito was heterosexual, homosexual, or indeterminable. The results confirm our prediction. Males composed more homosexual graffiti (29.1% within gender; see Figure 3) than females (17.5% within gender). The difference was significant, as indicated by a Chi-Squared analysis, χ2 (2, N = 366) = 13.74, p = .001 with an effect size of φc = .19 using Cramér's phi.

Research question one inquired which sex would produce the greatest amount of interactive graffiti. The data showed that females produced more interactive graffiti (6.7% within gender) than males (4.2% within gender). A Chi-Squared analysis revealed that the difference was significant, χ2 (2, N = 1201) = 7.36, p = .025 with an effect size of φc = .08 using Cramér's phi.

The second research question asked which sex would compose the most insults. Our results indicate that females authored more insults (11.1% within gender) than males (6.7% within gender). This difference was significant as indicated by a Chi-Squared analysis, χ2 (2, N = 11961) = 8.03, p = .018 with an effect size of φc = .08 using Cramér's phi.

Our third research question asked whether males or females would produce more graffiti indicating physical presence. Observing dominant frame, males produced more graffiti on physical presence (53.7% within gender) compared to females (40.2% within gender). As signified by a Chi-Squared analysis, this difference was significant, χ2 (6, N = 1201) = 95.71, p < .001 with an effect size of φc = .08 using Cramér's phi.

Hypothesis five predicted that males would draw more pictures compared to females. This hypothesis was partially supported. Males drew more pictures without words (4.8% within gender; see Figure 2) than females (1.3% within gender). However, females produced many more instances of pictures combined with words (28.7% within gender) than males (5.9% within gender). A Chi-Squared analysis revealed that the difference was significant, χ2 (2, N = 1198) = 94.66, p < .001 with an effect size of φc = .28 using Cramér's phi.

Finally, research question four asked which sex would produce the greatest amount of graffiti. Counting instances across the entire sample (N = 1,201), females produced far more graffiti than men: 777 (female) vs. 424 (male). However, due to the sampling technique of selecting stall walls (discuss above), these numbers are somewhat misleading. Calculated stall-for-stall, males produced nearly 3 times the amount of graffiti as females.

Discussion

The central aim of the current study was to examine differences between women’s and men’s graffiti from a perspective informed by previous research and evolutionary psychology. The findings suggest that significant gender differences exist in terms of the amount, type, and nature of graffiti. Although the results were mostly in line with previous studies’ findings, some notable differences stood out from existing research.

Concurrent with previous literature and evolutionary theory, males composed more sexual and homosexual graffiti than females. These findings were unsurprising as males are motivated to appear dominant through sexual conquest and to engage as many mates as possible, thus making them less selective about their sexual partners. Furthermore, we expected these results because homosexuals have sexual strategies very similar to heterosexuals. These results corroborate previous content analyses and the aforementioned psychology-based predictions. As a result, it is likely that graffiti may act as a cultural indicator as discussed by previous content analyses. Additionally, because certain evolved drives motivate people to express thoughts that long-standing sexual strategies govern, we argue that the content of latrinalia is subject to these motivations.

Our findings also supported the prediction that females would compose more messages that were romantic in nature. Because a major tactic females employ to prevent partner infidelity is to identify relationships, this finding was anticipated. However, the method females used was unexpected. We predicted that males would draw more pictures based on their greater receptiveness to images. Although our results confirm this finding, females authored far more images combined with text than males. Because we broadly defined pictures as any comprehensible non-verbal scrawling, the parameters included symbols such as hearts. Surprisingly, hearts were the most common pictorial graffiti. Females often included hearts within signatures, when professing friendship, love/relationships, and even when writing about schools, organizations, and sports teams. Males on the other hand, rarely included hearts, instead opting to draw standalone images (e.g., faces and phallic images).

The finding that females authored more insults concurred with evolutionary psychology but disagreed with previous research into graffiti (e.g., Burner & Kelso, 1980; Green, 2003). This finding identifies a key strategic difference among the sexes. Females are more likely than males to use verbal/textual relational aggression to derogate competitors. However, males composed more message indicating physical presence than females. Marking physical presence is akin to marking territory and thus, proclaiming resources and warding off competitors. In rationalizing this difference, it appears that males indirectly intimidate rivals and aim to impress mates using graffiti. Females, on the other hand, do not attempt to ascend above their competitors; rather, they use insults to bring their opponents down.

Limitations and Suggestions for Future Research

Although bathroom stalls are an excellent source of graffiti due to their privacy, future studies may want to expand beyond bathroom stalls and account for all bathroom graffiti (i.e., graffiti around urinals, mirrors, sinks, and on the main walls themselves). It would be interesting to compare how subject matter changes when no longer controlling for privacy.

In addition to only collecting graffiti from stalls, sampling bars and bar-restaurants may have confounded our results. It is likely that alcohol-induced patrons could have lowered inhibitions and thus, influenced the graffiti’s content. However, lowered inhibitions may have offered a more direct insight into sexual attitudes.

Additionally, geography may be a salient factor in sexual and socio-political issues as the study was conducted in a small Midwestern college town that is known for cultural diversity and progressive attitudes. Perhaps then, future studies should consider a comparative element that considers geography and select areas outside of college towns such as rural gas stations, small town public venues, large metropolitan restaurants and bars, and recreation centers to analyze a broad range of topics and ideas.

Finally, the current study did not account for time frame. In other words, the researchers were unable to distinguish when individual instances of graffito were authored. Nevertheless, most of the bars informed us that the stall walls were re-painted annually. Because of this, it is likely that this study observed mostly recent attitudes.

Conclusions

In sum, the present research aimed to identify gender differences within bathroom graffiti as indicators of long-standing psychological motivations. The findings illustrate a number of differences along these lines and identify the utility of evolutionary psychology as a predictive framework for people’s expressions. Furthermore, this perspective adds additional nuance and validity to previous conclusions surrounding graffiti, as well as challenges some existing knowledge.

In many ways, graffiti acts a perpetually present mouthpiece that identifies and celebrates humans’ primordial inclinations. Whether it is telling the world that Riley was here or that Riley loves Amir, these illegally etched messages exist as social artifacts that demand attention. From exulting pregnancy in a cave painting to insulting the chastity of a rival on a bathroom wall, graffiti concisely provide a provocative glimpse into contemporary attitudes, desires, and aversions.